POS0923 THE TRANSITION FROM ACTIVE LESIONS TO STRUCTURAL CHANGES ON SACROILIAC MRI AND ITS ASSOCIATED FACTORS
Authors: U. Kalyoncu, G. Ayan, L. Kiliç, P. Atagündüz, S. Akar, N. S. Yasar Bilge, E. Dalkiliç, Y. Pehlivan, O. Küçükşahin, C. Bes, H. Emmungil, D. Ersözlü, A. Ates, R. Mercan, G. Kimyon, S. S. Koca, E. Gönüllü, V. Yazisiz, N. A. Kanitez, A. Erden, B. N. Coşkun, B. Yağiz, S. Yilmaz, T. Kaşifoğlu, A. İ. Ertenli, S. Kiraz
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> Both active and chronic lesions can be seen on sacroiliac MRI. <h3>Objectives</h3> Aim was to compare the demohraphic and disease characteristics of patients with active and structural lesions on sacroiliac MRI in a bDMARD cohort of Spondyloarthritis (SpA) patients. <h3>Methods</h3> TReasure is a national, multicentre, longitudinal, and observational database, initiated in Turkey in 2017 and now includes 17 centres [1]. 1230/7015 (17.5%) patients with SpA [including Psoriatic arthritis (PsA)] had findings consistent with sacroiliitis on MRI that was recorded by the radiologist at each center for the presence of active and structural lesions. Demographic characteristics of the patients, SpA associated characteristics; dactylitis, enthesitis, uveitis, IBD, SpA family history, hip involvement, hip replacement, sacroiliitis by mNY, syndesmophyte. disease activity during bDMARD initiation; ASDAS-CRP, ASDAS-ESR, BASDAI, ESR, CRP, VAS (physician global, patient global), function and quality of life; BASFI (&gt;40 mm), HAQ-DI (&lt;0.5, 0.5-1.0, &gt;1.0), EQ5D, were assessed and compared between groups with active/ active and structural/structural lesions. <h3>Results</h3> Of 1230 patients with sacroiliac MRI, 548 (44.5%) had only active lesions, 418 (33.9%) had both active and structural lesions, and 264 (21.5%) had only structural lesions. The diagnoses of the patients were r-SpA 833 (67.7%), peripheral SpA 329 (26.7%), nr-SpA 321 (26.1%), enteropathic SpA 79 (6.4%), PsA 64 (5.2%). From `only active lesion` to `only structural lesion` on MRI, age was older, disease duration was longer, meeting mNY criteria and hip involvement was more common, HLA-B27 positivity was more common, syndesmophyte was more common, uveitis was more common, and metrological indices (BASMI and Schober`s test) was worse (Table 1). Multivariate analysis showed factors associated with the development of structural lesions from active lesions, disease duration with OR 1.09 (CI 95% 1.04-1.14), mNY positive sacroiliitis with OR 3.36 (95% CI 1.52-7.40) and uveitis with 3.80 (95% 1.23-11.8). <h3>Conclusion</h3> Transition from active lesions to structural lesions in sacroiliac MRI may be time-related, and chronicity develops in approximately 5 years. As expected, when structural lesions develop on MRI, the rate of meeting the mNY criteria increases around 3 times. There is a relationship between uveitis and the development of structural damage. The relationship of metrological indices with structural damage should also be considered. However, the lack of central reading in MR is a limitation in this assessment. <h3>Reference</h3> [<b>1]</b> Kalyoncu U, et al. Turk J Med Sci. 2018 Aug 16;48(4):856-861. <h3>Acknowledgements:</h3> NIL. <h3>Disclosure of Interests</h3> None Declared.